Abstract
In order to obtain high purity iron from chloride solution, a purification process by anion exchange and solvent extraction in hydrochloric acid medium has been developed. The purification by anion exchange consists of two steps, elution of FeCl2 and elution of FeCl3. Solvent extraction was carried out by using methyl-isobuthyl-ketone after anion exchange. The purified ferric chloride solution was evaporated to dryness in air, oxidized and thereafter reduced by Pd-purified H2.
Iron wire specimens 0.5 mm in diameter were obtained and then purified by wet H2, dry H2 and vacuum treatment. Electrical resistivity was measured on wire specimens at 4.2 K to obtain the residual resistivity ratio. Effectivity of each purification step was confirmed and the purified iron showed RRRH* of 1580. Elution of FeCl3 can be repeated easily and is known to be very effective, and the sample, purified through 2 passes of FeCl3 elution after FeCl2 elution, showed RRRH of 2600.
*RRRH; the residual resistivity ratio obtained by using the minimum resistivity under the application of longitudinal magnetic field of 750 Oe.
